Kougami unintentionally revives Gara, one of the alchemists who created the Core Medals 800 years ago, while trying to find the Lost Medal. Gara transposes a section of Japan with a section of Germany and begins to amass Core Medals from OOO and the Greeeds. Eiji teams up with Tokugawa Yoshimune and eventually with the other Greeeds to stop Gara from ending the world.

Based on a baboon with features of a leopard and snake, it was created by Gara to get Ankh and Eiji's Core Medals. It has the capability of shooting fire amd jumping great distances. It speaks through the skull on its left hand and can act independently from the main body.

One of the four alchemists from 800 years ago who created the Core Medals. Created the Gaja Medal which can hold each of the Core Medals in it. However, this power was sealed away by the king from 800 years ago. Ironically, it was the king's descendant, Kougami, who removes this seal. Gara used all of the Core Medals to become his true form called Gara Dragon.

Edo Bakufu's eight shogun. Went among his people as the poor samurai Tokuda Shinnosuke (徳田新之助). Also sings in the ending song, Te Wo Tsunagou. This character is from a TV show called Abarenbou Shogun, and the same actor plays this character in both.

When Eiji is flipping through the channels on the TV, the opening logo for Abarenbou Shogun appears.

When Hina throws Date's Medal tank to Eiji, he replies back to Hina with "Hina-chan, nice". It's very similar to how Date replies back to Gotou when he does something good.

When Eiji transforms into Birth, he does the Medal flip like Date but when putting the Medal into the Birth Driver, the motion is similar to how he moves the OOO scanner

This is the only time when Eiji becomes Birth.

Ankh gives up his personal Medal to Eiji so that he can transform into OOO. The only other time this happens is in the TV series finale.

When Shin-san rides in on his horse, a castle can be seen in the background. In this scene he's wearing a robe and brandishing a sword with the Tokugawa Crest, yet Eiji still refers to him as Tokuda-san. Kamen Rider Poseidon's belt sort of looks like the Tokugawa Crest upside down. He also has purple swords. Purple being a color usually just for royalty. Burakawani form, which uses the Tokugawa Medals, also has purple eyes.

Of the OOO clones, the real one would have to be either the Tatoba or Burakawani forms, since only the original would have those Medals. At the end, the only one left is the Tatoba form, so the Burakawani one was just a clone borrowing the Tokugawa Medals. The real one could be Putotyra as well since those Medals only exist inside of Eiji's body.

At the end, Shun's mother asks Shun to pick between two presents, in the same way Bell offered a choice. Since Gara is probably male, it's probably okay to conclude that Bell is an offshoot of Shun's mother.

When Ankh holds Hina's hand, it's with the right Ankh hand. Hina, Ankh, and Eiji all hold hands again in the last episode too.

The ending animation that runs during the ending song is a puppet theater-looking retelling of the movie's story. The animation is something like Terry Gilliam's work on Monty Python.

Movie is named Wonderful, the English equivalent to Kougami's frequently shouting "Subarashii!"

Gara's giant Medal can be seen in Kougami's treasure room in the last few episodes.

The Cobra, Kame and Wani medals make a cameo appearance in the finale.

Reasons that it's not canon

People have stated that there is never a time when Eiji has the combination of Medals that he does in the TV series, but this was probably just an unimportant detail that was ignored.

Burakawani form is never seen in the TV series, nor are the events in the movie mentioned in the TV series.

The Greeeds joining together and Date still being Birth isn't possible. When Mezool and Gamel are revived, Uva lost his body afterwards. When Uva finally joins with the rest of the Greeeds, Date isn't Birth anymore. Also, Lost Ankh doesn't appear in the movie at all.

An extension of the movie with additional footages that are not shown in the theatrical cut.

It should be noted that this is the first Kamen Rider movie director's cut to be released on Blu-ray. All previous director's cuts have been released on DVD only. The back of the cover claims that there are about seven minutes of new footage.

Scene of Tokyo's city in Germany. It looks like a bad Photoshop job, which might explain why it was cut.

Eiji comforting the boy scene is extended.

Girls with the top-knot hair style.

Shows the ancient king killing Gara in the past. Gara was working on the Burakawani Medals at the time, maybe that's why that set was never completed.

Extended Chance Time scene.

An additional line by Gara after switching a portion of modern day Japan with Edo and minor rearrangement during that scene.

Date looking around for his Medal tank before realizing he lost it on the other side.

When Gara created the Nue Yummy, he said that Eiji is no longer needed since he's OOO now and can live until Eiji stops giving Medals.

Eiji doing a poor job explaining the situation to the villagers.

Eiji mentioning Date's Cell Medals when Ankh needed to recover.

Chiyoko handing out ice cream to the villagers scene extended.

Date and Gotou pondering their next move is extended at the beginning along with a small extension of Chance Time.

Small extensions after part of Japan is flipped with Jurassic era Japan with Date and Kougami getting some additional lines. Gara notes that one more before he becomes OOO before cutting to the real world view of the scale.

Minor changes during the scene where Date and Gotou examine the barrier.

Hina puts a blanket on Ankh as he sleeps.

Kougami messing with his top-knot in a mirror.

Gara accepting Kougami's request is slightly extended.

Gotou and Data load the Birth Buster cartridge for the attack on the barrier.